XNA Shaders

• http://www.syntaxwarriors.com/2012/xna-alpha-mapping-with-pixel-shaders/
• http://www.gamedev.net/topic/573961-how-to-set-depth-value-in-pixel-shader/
• http://msdn.microsoft.com/en-us/library/windows/desktop/bb944006(v=vs.85).aspx#Inputs_and_Variables

• http://www.riemers.net/eng/Tutorials/XNA/Csharp/Series3/Pixel_shader.php